On Some Themes in Parmenides

Transcription

1 Mortenson, Chris On Some Themes in Parmenides. In M. Rossetto, M. Tsianikas, G. Couvalis and M. Palaktsoglou (Eds.) "Greek Research in Australia: Proceedings of the Eighth Biennial International Conference of Greek Studies, Flinders University June 2009". Flinders University Department of Languages - Modern Greek: Adelaide, On Some Themes in Parmenides On Some Themes in Parmenides Chris Mortensen Parmenides has been widely regarded as someone whose main assertions are outrageously false, since he seems to have denied change, motion and diversity. In this note I will show that, while there is some justice in the received view, nonetheless there are important insights to be gained from taking his position seriously. Along the way, I will register agreement or disagreement, where appropriate, with the papers by Scott Mann and Peter Woolcock in this volume. My final position is more in agreement with Mann than Woolcock, though I have disagreements with both. 1. The uses of is A. J. Ayer once described the modern European philosophy of existentialism as the systematic abuse of the verb to be. As we will see below, Parmenides appears to have got himself into confusion over is, and its cognates such as being (on to). To clarify: there are three semantically distinct uses of the verb to be. First, we have the locution Smith is, which is one way of saying that Smith exists, which we can call the is of existence. In the notation of modern logic, this can be written ( x) (x=s). Second, there is the locution Smith is tall, which is called the is of predication, and is written T(s). Here some property is attributed to Smith. Third, there is the locution Smith is the man I met yesterday, which is called the is of identity, and written s=(ιx)mx, or more simply s=m. The difference between the second and third senses is as follows. With the is of predication, tallness is in no way claimed to be unique to Smith, having rather the character of a universal, that is being generally multiply instantiated. In contrast, with the is of identity, the man I met yesterday is a unique man, not multiply instantiated. 2. The non-existent cannot be spoken about or thought about Now Parmenides and his contemporaries seem not to have distinguished at least the first and second senses of is. This conflation invited him to draw the conclusion that 79

2 Chris Mortensen that which is not, i.e. that which does not exist, cannot be spoken about, that is cannot be the subject of (true) predication. A variation is the claim that the non-existent cannot be thought about. After all, to say or think that Smith is tall is to imply that Smith is, that is, Smith exists. Contraposing then, one cannot make any true assertions about non-existent things. Now, as Woolcock points out, following Anthony Kenny, this is simply a non sequitur. Plainly we do speak truly of the (now) non-existent, as in Caesar conquered Gaul, and even of the never existent, as in Bellerophon rode Pegasus. I don t mean that these two examples are semantically the same, nor even that they are semantically unproblematic. I only wish to point out that Parmenides seems to have argued in the indicated way, and so is open to this objection. Obviously the same objection applies to the variant thesis that the nonexistent cannot be thought about. Indeed, it is characteristic of our thinking that we are able to consider imaginary scenarios about non-existent things. As Popper noted, we send our thought-experiments to die in our place. 3. Nothing cannot exist However, Parmenides uses this incorrect view to derive a correct and important conclusion, namely that the nothing, or nothingness, cannot exist. I wish to endorse Parmenides strongly here. It annoys me greatly to read titles such as Jean-Paul Sartre s Being and Nothingness, where to speak of nothingness gives a spurious air of profundity. Heidegger and his students, as Sartre was, are particularly fond of this way of talking. Against the purveyors of The Great Nothing, let me say that nothingness is not the kind of thing to exist. The word nothing is not properly a noun. Rather, locutions using nothing are elliptical ways of denying existence. Nothing is tall does not mean that there is a thing, the nothing, which is tall. It means that there does not exist a thing that is tall. Indeed, the ellipsis is only barely concealed: it can be rewritten as No thing is tall, that is Aristotle s E form, which makes the negative existential claim evident. Having said this, it is nonetheless remarkable that mathematics has found a principled use for nouns which apparently denote null entities, such as the number 0, or the null set {}. This might seduce us into thinking that since we can think about 0 or {}, such surrogate nothings must in some sense exist. Worse, applying to mathematical theories the usual logical device of existential generalization over singular terms requires us to conclude that they exist. That is, 0 = 0 therefore ( x)(x = 0). There is a good PhD thesis to be written on the semiotics of nothing, (don t tell the taxpayer!), to explain this phenomenon. Even so, it does not go against my claim that the use of words for nothingness is to deny existence. We write The rest mass of the photon = 0 when we could also assert the negative existential There does not exist a rest mass for the photon. We write that the intersection of the sets A and B is the null set, A B = {}, when what this means that there does not exist anything which is a member of both the sets A and B. 80

3 On Some Themes in Parmenides So Parmenides is right to deny the existence of nothing, and importantly so. But what can be made of it? 5. There is no change, no beginnings nor endings. Nothing can come from nothing Parmenides famously denied temporal change. His follower Zeno followed up with some clever arguments designed to support this denial, particularly as applied to motion. His argument on this point seems to derive from the prior thesis that a thing cannot come into existence, nor go out of existence. In short, there are no beginnings nor endings. In turn, this is deduced from the premiss that nothing can come out of nothing. For, if nothing can come from nothing, then, since to come into existence is to come from nothing, it follows that nothing can come into existence. Another way to put the conclusion is that newness can t happen, for newness is likewise something which comes out of nothing. By similar reasoning, too, nothing can go out of existence, since that would be to go into nothing, which does not exist. But then, change is newness, new existence or new non-existence. Hence, change is likewise something come from nothing or going into nothing, which does not exist. Thus change is denied. This is ingenious, worthy of a clever philosopher, but it is fallacious. The negative-existential account of nothing-discourse, which I outlined above, clarifies. If nothingness is not a kind of thing, then change can be present, in the sense that the new event merely lacks an origin to come out of. Parmenides has another argument at this point. Change (over time) involves something ceasing to be in some state S and coming to be in some incompatible state not-s. So in some sense, Parmenides is claiming that change is inconsistent and so cannot exist. Here he is agreeing with Herakleitos that change is inconsistent, but disagreeing in that he concludes that change is to be denied. Herakleitos is the initiator of a tradition which includes Hegel and Graham Priest, who argue that the correct analysis of real temporal change, is precisely the presence of an inconsistency. For example, considering the motion of a particle X, it takes the form X is at point P and X is not at point P. Like Herakleitos, these later thinkers are not denying real contradictions. To the contrary, they are saying that contradictoriness is the stuff of change. That is, both sides in this matter accept the inconsistency of change, but are opposite on whether change and inconsistency are real. Lest we think that the denial of change is too absurd to be countenanced, Scott Mann makes well the point that a good model for the Parmenides denial of a changing universe is spacetime, the so-called block universe of Special Relativity, SR. Here, all times, past present and future, are equally real. Hence in a sense Parmenides thesis that nothing comes into existence is vindicated, in that all its temporal parts are real together. Opponents like Herakleitos and Hegel are among the presentists. Presentism is the thesis that only the present is real. Presentism and SR are certainly at odds 81

4 Chris Mortensen with one another, since SR postulates that there is no natural simultaneity relation between events in space-time, whereas presentism provides us with one, in the form of the moving edge of existence, since neither the past nor the future exist. However, as John Bigelow points out, SR is not incompatible with a distinguished simultaneity relation, merely does not entail it. Thus the modern physics of spacetime supports a static, block universe, and in that sense temporal change as successive becoming is denied. In this sense Parmenides is to be favoured over Herakleitos. But this position must then answer a challenge, namely that it flies in the face of common experience to say that there is no change and motion. The theorist of spacetime must therefore at least explain Parmenides of Elea away the overwhelming intuition that the present moves, and existence moves with it. Scott Mann agrees, and supposes that it must reflect some real, structural features of the world. As an example, it can be said that common to our experiences and the things they are experiences of, are (by and large) their temporal order. Here I think that we can go further, with Hegel s help. He always insisted that he was an idealist that is, only ideas exist. Now idealism is untenable, as just about everyone these days agrees. Still, Hegel s philosophy, and in particular his contradictory account of change, might apply as a description of the ideal world, the mental world, as it exists within our physical world. That is, we might say that the phenomenology of change is distinguished by being inconsistent. It is hard to escape this conclusion when one reflects on the origins of the pheno menology. It seems that there are various levels at which the comparison between events close in time is made in the perception of motion. Some of it is purely retinal. Other components are fast, relying only on the perception of motion by itself, without much detail about the moving things. Other aspects of the phenomenology of motion involve illusions of motion, which strongly suggest higher-order processing. But overall, it simply must work on various levels by having a data stream read into a buffer, where successive moments are superimposed, for comparison. (I owe these points to Jon Opie.) Difference, incompatibility, is the source of the judgement of motion. It is what explains the phenomenology of the perceived event, thought not, I suggest, the event itself. 82

5 On Some Themes in Parmenides 5. There is no spatial differentiation (all is one) Another seemingly outrageous thesis of Parmenides is that there is no difference across space. He argues that there is no spatial differentiation. In this I will argue that he goes too far. Parmenides argument is that if things were to be different they would be spatially distant. But spatial distance is no distance, since space is a nothing. Things with space between them have nothing between them, thus they are contiguous and so not distinct. An effective reply to Parmenides is to suppose that empty space is not a nothing, rather it exists. This is the contention of spatial realism. This is the thesis, held by Newton and recently by Graham Nerlich, that space exists. However this begets the response that spatial realism is in trouble with the Principle of Sufficient Reason PSR, as Woolcock notes. The PSR is the thesis that everything has a sufficient reason for existence. This principle was used by Leibniz against Newton. Leibniz argued that if space were real, a kind of container of bucket for physical things and events, then there would be no sufficient reason for why it were created in one place, or everything shifted one kilometer to the west. But there is a deeper argument against spatial realism in Parmenides, I think. This is the argument that if we had two things separated by empty space, then each thing and the space formed a unity, as there was literally nothing between them. This is the suggestion that two spatially separate things have literally no existing thing between them. This is a kind of unity. Where I think this argument breaks down, can be illustrated by the example of surfaces. Surfaces bound a continuous volume. But they really do seem to mark the world at its joints. All of matter up to and including a surface is one part of the world, and the remainder, the space outside the other surface, is another. This is obviously carried by the presence of some physical parameter (such as non-zero mass-density) in one of these parts, and its absence in the other. 6. The Possible Woolcock makes an interesting suggestion. He takes up the earlier point that Parmenides is proposing a criterion of thinkability, namely existence. Woolcock proposes that the thinkable is the consistent. Woolcock appeals then to David Lewis modal realism, according to which all possibilities exist equally, as possible worlds inhabiting logical space. Thus, consistency and possibility coincide, and both coincide with the totality of (existing) possible worlds. This then serves as a model for Parmenides equation of thinkability with existence. In passing, Woolcock expresses skepticism over modal realism, along with just about everybody else (myself included). However skepticism about the link between possibility and existence does not erase Woolcock s other premiss, that the thinkable is the consistent. 83

6 Chris Mortensen But the latter premiss runs into two objections. First, the possible surely extends beyond the consistent, or at any rate the thinkable does. The inconsistent has a structure, which shows that it is thinkable. Second, it runs into a variant of Priest s inclosure scheme (see his [2002]). The inclosure scheme applies to a certain very general kind of position, familiar in many philosophers over the ages, which offers necessary and sufficient conditions for some general concept, such as thinkability. The inclosure scheme is a proof that such a position is contradictory. The position involves conditions C, of one kind or another, for thinkability: T C. But the negation of the condition C is immediately thinkable, that is T & ~C, which is in contradiction with T C. Thus according to Priest, all theses about the limits of thought are contradictory. And thus we can apply Priest s reasoning to the claim that the thinkable is the consistent. For if consistency is thinkable, so is inconsistency: simply insert not. Priest, theorist of the contradictory as he is, celebrates this conclusion as one more vindication of true contradictions; but I do not think that Woolcock would feel comfortable with true contradictions. 7. Conclusion Parmenides is arguably the first real philosopher. By that I mean that he argued for his views, unlike for example Herakleitos or Lao-tsu, who were more given to oracular pronouncements. Parmenides views on change and existence have sounded strange to many. We have seen, however, that there are aspects of his views that invite agreement in the light of developments much later in physics and philosophy. At the very least, Parmenides position encourages metaphysical speculation of the kind we have been doing in this essay. That is the mark of a philosopher who has had something worthwhile to say. Bibliography Priest, 2002 Graham Priest, Beyond the Limits of Thought, Oxford: Oxford University Press. 84